Heating apparatus and method



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HEATING APPARATUS AND METHOD File Mag" 8, 1929 2 Sheets-Sheet Nov, 22,1932. NASH AL 1,888,804

HEATING APPARATUS AND METHOD Filed May 8, 1929 2 Sheets-Sheet 2 ffH'HHTfffffff/fff/ff 9 4, 4t 65 '.i. K 68 9 a5 I 4 1 aa6 i A 1 23%Fer-tented Nov 22,, 1932 ARTHUR E. NASH, 0F PHILADELPHIA, AND JAMES S.ALCORN, ()F CYNWYD, "FENBTSYTIQ VANIA, ASSIGNORS T0 ALCORN COMBUSTIONCOMPANY, OF JPMLADELFHIA, PENN- SYLVANIA, A CQRIPURATIQN 012" DELAWAREHEATING APPARATUS AND TIZJE'J'LE JOD Application filed May a 1929.Serial No. 3 1,290. I

Our invention relates to heating systems, and more particularly toasystem for generatin g heat by com ustion for furnaces, heatingsystems, and t e like, in general, and more particularly for oil stills,steam generators and the like.

In accordance with our invention fuel, in the form of gas, vapor, liquidor finely divided solids, is delivered under pressure from nozzlestructure or equivalent to produce a jet or jets operating as a motivefluid for ontraining combustion-supporting air whose pressure is raisedby injector or e]ector operation or aspiration and delivered with and bythe fuel jet into a combustion zone or chamber comprising a nozzlepassage in which the air and fuel are intimately mixed and the fuellargely burned; and preferably the gases soon after their discharge fromthe nozzle-like combustion chamber and before they impinge upon the heatabsorption strucinduction of the combustion-supporting air is wholly orsubstantially wholly independent of orwithout reliance upon the stackdraft Which is utilized only for carrying off products of combustionafter they shall have completed their course through the heating systemor furnace.

Further in accordance with our. invention the combustion-supporting airinduced by the burner jet'action is drawn either directly from theatmosphere, or from the atmosphere through a preheating system.

Our invention resides in a system and in features of construction andarrangement of the character hereinafter described and claimed.

For an understanding of our invention and for an illustration of severalof the various forms our structure may take, reference is to be had tothe accompanying drawings, in which:

Fig. 1 is a vertical sectional view, parts in elevation, of structureembodying our invention. J

Fig. 2 is a horizontal sectional View, parts in plan, taken on the line22, Fig. 1.

Fig. 3 is a vertical sectional view taken on the line 33 of Fig. 1.-

Fig. 4 is a vertical sectional View, parts in elevation, illustrating amodification of our structure.

Fig. 5 is a vertical sectional view, partly in elevation, taken on theline 5-5 of Fig. 4.

Fig. 6 is a fragmentary horizontal sectional view illustrating structuresimilar to a part of that illustrated by Figs. 4 and 5.

Referring to Figs. 1 to 3 inclusive, 1 illustrates a floor or foundationof a furnace or similar structure having the vertical wall 2 surmountingthe foundation wall 3.

lln the wall 2 is formed an opening 4:, constitutingan air or suctionchamber, covered (Fill at its front by a casting or plate 5 itselfprovided with an air inlet opening 6 with which co-acts the cover ordamper 7 pivoted at 8 and carrying the toothed segment 9 engaging thelower edge of the opening 6 to hold the member 'Z -in any suitablyadjusted position.

The inner or furnace-chamber end of the air chamber 4: is closed in partby the pier l0 and the Venturi block or nozzle block 11 convergentnozzle passage 12 communicating, in

the example illustrated, immediately with the divergent nozzle passage13, with which latter communicates the chamber -14 having refractory orfire clay Walls. The bottom wall is formed of slabs 15 lying upon thesupport 10. The sidewalls are formed of slabs or superposed elements 16,and the top by slabs or elements 17. In the example illustrated thechamber 14 may be of any suitable length, and ordinarily will be of theorder of three or four feet long.

While the nozzle block or Venturi element 11 is illustrated as havingtheconvergent divergent nozzle passages 12 and 13 communicating. directlyor immediately with each other, it will be understood that between theseconvergent divergent portions may be a cyllindrical portion of anysuitable length, constitutlng the throat which in the exampleillustrated however, is at 18 at the junction of the passages 12 and 13.

It shall further be understood that the nozzle or Venturi element 11 mayhave only a convergent passage, generally similar to 12, delivering intothe chamber 14.

lit shall further be understood that whatever the structure of thenozzle or Venturi element 11, it may, in lieu of discharging into theshort Combustion chamber 14, discharge directly into the furnace chamberG which lies to the right of the wall 2, and in or be- .yond which islocated any suitable heat absorption structure, of tubular or any otherform, containing the material to be heated, such as fluid, andparticularly oil or petroleum to be distilled or cracked, or water to beconverted into steam. Suitably positioned with respect to the inlet ofthe nozzle passage 12 is any suitable burner structure to which fuel, inany suitable form, is delivered under pressure and discharged into thenozzle passage 12 in the form of a jet, which operates as motive fluidto entrain combustion-supporting air drawn from chamber 4 and forcedthrough the nozzle member 11, causing intimate mixture at hightemperature of fuel and air which is promptly and rapidly burned to astate of substantially complete combustion before the gases aredischarged to any considerable distance beyond the right end of thecombustion chamber 14, Figs. 1 and 2, into the furnace chamber C. Or, inthe ab sence of the chamber 14, when the gases are discharged directlyinto the chamber C their combustion is substantially complete before thegases have passed to a considerable distance into the chamber C. Ineither case substantially no unburned fuel reaches heat absorptionstructure in the furnace chamber C. When the chamber 14 is utilized itin effect constitutes a part of the, entire nozzle or Venturi structure,which is similar to a combining chamber, combining cone or diffuser ofinjector or ejector apparatus.

Presented to thenozzle passage 12 is the burner or nozzle 19 upon theend of the conduit or pipe structure 20 through which is delivered fuelin suitable form, more particularly oil, preferably atomized by steam,and in any event delivered undersuch pressure as to cause the fuel toissue as a motive fluidjet from the burner or nozzle 19. The steam,under any suitable pressure, for example of the order of pounds persquare inch gauge, is delivered to the structure 20 through the-pipe 21,and is controlled by the valve 22. The oil enters by pipe 23 controlledby valve 24. The jet of fuel, or of oil and steam, issuing from theburner or nozzle 19 forms a high velocity/motive fluid jet whichentrains air from the chamber 4, forcing it eeaeoa into the nozzlestructure 11 at suitably high velocity. The fuel from the nozzle 19 andthe air become rapidly intimately mixed at high temperature within thenozzle structure 11 and combustion takes place rapidly and substantiallycompletely before the gases travel a substantial distance into thefurnace chamber C in case the chamber 14 is materially shorter thandescribed, or omitted entirely. In this connection it will be understoodthat the nozzle memberllmay itself be prolonged and extend a suitablyshort distance into the chamber C, when the structure forming thechamber14 is absent. In any event the nozzle passages 12, 13 and thechamber 14, which may diverge in continuity of divergent passage 13, maybe considered as those of a single nozzle structure, or combining tubeor venturi.

The combustion within the nozzle structure, which includes in most casesthe short chamber 14, is rapid, due to intimate mixture of air and fuelat high temperature, and

there is discharged into the heating cham-' ber C a dame in which thebalance of the unburned fuel is rapidly consumed, whereby the gasesimpinging upon the walls of the chamber (1 or upon any heat absorptionstructure which may be therein disposed, is devoid of unburned fuel,thereby avoiding injury to the walls or heat absorption structureotherwise occurring because of presence of substantial amounts ofunburned fuel.

In addition to the nozzle 19, or, and preferably, associated therewith,is the annular nozzle structure 25 comprising the annular or manifoldchamber 26 surrounding the central air passage or open space 27 withinwhich is disposed the nozzle 19, when employed. Fluid in suitable formis delivered into the annular chamber 26. For example fuel gas isdelivered through either or both of the pipes 28 and 29, under anysuitable pressure, for example of the order of 15 pounds per square inchgauge. The flow of gas through the pipe 28 is nicely con-. trolled bythe valve 30, and the fuel delivered through the pipe 29 is controllableby the valve 31. At the forward end of the nozzle structure 25 is acircumferential series of small nozzles 32 delivering jets of fuelmerging into an annular jet serving also as amotive fluid jet forentraining and forcing air from chamber 4 into the nozzle structure 11.The forward outer portion of the nozzle structure 25 is tapered inwardlyand forwardly as indicated at 33 to form with the adjacent wallstructure and/ or nozzle structure 11 an outer annular air passage 34through which air is induced by jet action into nozzle member 11.

With either or both of the fuel jet systems in operation, air isentrained from the chamber 4 and induced or forced in a stream boththrough the passage 27 and around the messes exterior of the nozzlestructure 25 into the nozzle or diffuser structure 11. Fuel from bothnozzle structures, for example oil from. one and gas from the other, isintimately and rapidly mixed with the induced air and prompt y burned,whereby the products of combustion projected into the furnace chamber Ccontain little or substantially nounburned fuel.

When steam under pressure is utilized, as above indicated, it too servesto produce a motive fluid jet for ejection of air from the chamber 4into intimate mixture with the fuel in the nozzle structure 11, or 11and 14, this latter nozzle structure of whatever particular arrangementor form being in effect a so-called reverse nozzle or diffuser.

The furnace structure may have a singl chamber C, or there may be aplurality of chambers or zones traversed in succession by the productsof combustion. Heat absorption structure of any type, tubular orotherwise, may be located in any one or more of the zones, and in suchrelation as to absorb heat delivered thereto either by radiation orconvection, or both.

By recourse to an operation of the character described, involvingejector, injector, or aspirator action, the stack draft is not reliedupon tocause a flow of air into the combustion system; on the contrarythe jet action forces the air into the combustion system, at the sametime causing intimate mixture thereof with the fuel for very rapid andsubstantially complete combustion within a short distance from the pointof issue of the fuel from the burner or nozzle structure. Such draft asthe stack is capable of producing is utilized, preferably, simply forwithdrawing from the furnace the spent gases or products of combustionafter they have performed their useful work within one or more furnacechambers.

While not essential, the side and/or mp walls 16 and 17 of the chamber14 may comprise silicon carbide' or other highly refractory material ofhigh heat conductivity, so that these side and top walls operate assources of radiant heat to be absorbed by heat absorption structurewithin the chamber C suitably positioned with respect to these radiatingwalls.

Vl/hile the passage with n the nozzle member 11 will ordinarily becircular in cross section, it shall be understood that any othersuitable c oss sect on as elliptical, oval, or polygona. nay beutilized; and that in genera] the nozzle structure 25 will be of atleast generally sim lar configuration.

In Figs. 4 and 5 a structure, generally similar to that above described,is utilized, preferably in multiple unit array.

In the arrangement of Figs. 4 and 5 the combustion-supporting air isdelivered into the chamber 4 through the ducts 35 and 36,

the former of cast iron pipe, for example, and the latter formed withinthe brick or masonry work and covered by sheet iron or cast iron plates87 which are in turn covered with sheet asbestos 38 and fire brick 39.The [9 plates 37 may have the downwardly and inwardly extending integralheat conducting ribs 37a. T he neighboring and parallel ducts may becross connected by one or more headers 40.

The air entering at the right of ducts 35, Fig. 4, from the outeratmosphere, is preheated within these ducts before reaching the chamber4 from which the preheated air is then ejected by the jet operation ofthe burner structures into the nozzle type combustion chamber generallyof the characterhereinbefore described. The air in the ducts 35 is firstheated by the hot gases passing over the bridge wall 41 between it andthe furnace wall 42 on their way to the outlet 43 which connects to thestack. The remainder of the ducts 35 is heated from the hot gases withinthe chamber C as is the case also with the air as it further progressesthrough the ducts 36.

The movement of air through the preheating ducts 35 and 36 is caused orinduced by the ejector apparatus, drawing it into the suction chamber 4and then forcing it into the nozzle type combustion chamber.

In this particular example the heat absorption structure is a shell ordrum 44 which may be a steam generator, petroleum still, or the like.

Fig. 6 shows three nozzle type combustion chambers related to thefurnace chamber C, it being understood however that any suitable numbermay be employed depending upon the size or capacity of the furnace orheating system which they serve. It will further be understood that thecombustion units of the character described may be argaitilged inhorizontal or vertical array, or

While in the foregoing description the fuel, or fuel and steam has orhave constituted the motive fluid jet or jets, and thecomhustion-supporting air has been the fluid operated upon by such jetor jets, the reverse 115 act on or arrangement is contemplated withinour invention. That is to say the combustion-supporting medium, as air,may be utilized for producing the motive fluid jets, and the fuel,solely or in m xture with other 120 material, as steam, may be the fluidoperated upon and injected or ejected by the jets.

What we claim is: y

l. The method of burning fluid fuel, which comprises delivering the fuelunder pressure 128 to produce an annular jet, delivering fuel underpressure to produce a jet within said annular jet, cntrainingcombustion-supporting fluid by said jets and forcing it in streamswithin and without said annular jet and 1% around said second jet intoand through a nozzle passage, and therein effecting intimate mixture ofthe fluids at high temperature and rapid combustion of the fuel.

2. Fuel burning structure comprising a nozzle member, an annularmanifold, means for delivering fuel into said manifold, said manifoldhaving outlet structure producing an annular jet of fuel discharginginto said nozzle member, said nozzle member having a convergent inletand said manifold having periphery converging in the same direction withsaid convergent inlet of said nozzle member, said fuel jet being sorelated to the inlet of said nozzle member that air is en trained andforced into said nozzle member through the annular jet and between theconvergent Walls of said manifold and nozzle inlet passage 3. Fuelburning structure comprising a nozzle member, an annular manifold, meansfor delivering fuel into said manifold, said manifold having outletstructure producing an annular jet of fuel discharging into said nozzlemember, means delivering into said nozzle member a fuel jet Within saidannular jet, said jets so disposed with respect to the inlet of saidnozzle member that air is entrained and forced into said nozzle memberWithin and Without said annular jet and around said second named jet,

l. Fuel burning structure com rising a nozzle member, an annular manifod, means for delivering fuel into said manifold, said manifold havingoutlet structure producing an annular jet of fuel discharging into saidnozzle member, said nozzle member having a convergent inlet and saidmanifold having a periphery converging in the same direotion'vvith saidconvergent inlet of said nozzle member, means for delivering a fuel jetWithin said annular jet, said jets being so disposed With respect to theinlet of said nozzle member that air is entrained and forced into saidnozzle member between said jets and through the passage formed by theconvergent Walls of said manifold and the inlet passage of said nozzlemember,

5, Fuel burning structure com rising a combustion chamber in the form ofa nozzle passage convergent at its inlet, means for delivering fuel inthe form of an annular jet discharging into said convergent inlet, andmeans for producing a jet of atomized liquid fuel Within said annularjet, said jets so related to said convergent inlet that air is en-=trained and forced into said nozzle passage to eiifect therein intimatemixture of the air and fuel and rapid combustionof the fuel.

ARTHUR E. NASH. JAMES S. lhLCQlltN.

assesses

